The Northwest region is expected to experience between 5 and 30 fewer days per year with a minimum temperature below 10 degrees Fahrenheit by the middle of the century, and the coldest day of the year will warm is projected to warm by 7.33°F.

The largest decreases are expected in the inland of the region, particularly in high-elevation areas in central Idaho. The smallest decrease in cold days is expected coastal and southern parts of the region, where these kinds of cold days rarely occur. Similarly, high-elevation areas are expected to have up to 40 fewer days with a minimum temperature below 32 degrees by the middle of the century, particularly in the mountains of Oregon and Washington, and northern Idaho.